Li Guiyan

Determination of Critical Conditions for Initiation of Dynamic Recrystallization by New Method

ABSTRACT Based on the stress versus strain relation for materials at high temperatures, a new method to determine critical conditions for initial dynamic recrystallization (DRX) was proposed by analyzing the stress versus strain curve in a double natural logarithm coordinates (Ln–Ln plot) directly. The critical conditions of initial DRX of a low carbon steel were determined by the new method and the resultant values were compared with those determined by previous methods. The results show that the normalized strains are 0.6491, 0.7026, and 0.7055, respectively, by using the corresponding curves and all of the values fall in the range of 0.6–0.85 proposed by Sellars. The normalized stress and strain determined by using the strain hardening rate versus stress curve have a good agreement with those determined by using the stress versus strain curve in an Ln–Ln plot.